The initiation of sporulation in Bacillus subtilis is genetically controlled by a number of loci. These loci, spoOA, spoOB, etc., are highly pleiotropic, preventing the synthesis of all sporulation related sporulation functions. The major goal of the proposed research is to isolate and characterize the products of the spoO loci and to determine how these products control the initiation of differentiation. This goal is being approached by the molecular cloning of these genes. A small, multi-copy plasmid originally isolated from Staphylococcus aureus is the vector being used in this study. Recombinant plasmids are being formed by restriction nuclease digestion and ligation of plasmid and chromosomal DNA. These plasmids, replicating in B. subtilis will be analyzed in a minicell system to determine the products of the various loci.